Former radiation worker Medical Surveillance Program at Rocky Flats.

The United States Department of Energy (DOE), Office of Occupational Medicine and Medical Surveillance, has supported an ongoing Former Radiation Worker Medical Surveillance Program at the DOE Rocky Flats site since 1992. The program currently is managed for DOE by Oak Ridge Institute for Science and Education through a contract with Oak Ridge Associated Universities. Participation in the program is entirely voluntary and provides former Rocky Flats workers who were exposed to radiation with long-term medical monitoring and an update to the assessment of their radiation dose. Program participants receive medical examinations and in vivo and in vitro bioassay measurements of residual radioactivity. Radiation doses to participants are largely a result of internal depositions of plutonium and its radioactive decay products. The causes of many of the higher internal doses were accidents that generally are well documented. Former radiation workers are invited to participate in the program if they meet specific criteria for radiation exposure. Informed consent is documented using a consent form approved by an Institutional Review Board. Demographic, medical, and dosimetric information is maintained in a computer database and will be evaluated for any trends or correlations between exposure and health outcome.

Interactive brain atlas with the Visible Human Project data: development methods and techniques.

A prototype of an interactive digital brain atlas was developed by using the Visible Human Project data set of the National Library of Medicine. This data set provides corresponding axial magnetic resonance images, computed tomographic images, and cryosections of the brain. The prototype was developed to demonstrate the techniques and methods that will be used throughout the development process of the atlas. The atlas has a graphical user interface, supports user interaction with various representations of the brain (i.e., two-dimensional and three-dimensional [3D]), and displays multiple images simultaneously. Motion sequences of the 3D brain were incorporated in the atlas to provide an important link between two-dimensional brain slices and volume-rendered 3D anatomic structures. Volume visualization tools were used to interactively render, rotate, and reslice the volumetric brain data. The brain was segmented with manual tracing, thresholding, and morphologic algorithms and then rendered with volume-rendering tools.

The QT interval and serum ionized calcium.

The correlation between serum ionized calcium (Ca++) levels and three ECG QT intervals (Q-OTC, Q-ATC, and Q-ETC) was assessed in 20 adult patients. The relationship between each QT interval and Ca++ level, based on 209 Ca++ determinations through a range of 1.0 to 4.0 mEq/liter, is best described by a hyperbolic function. Although Q-OTC and Q-ATC predict Ca++ levels more accurately than Q-ETC, all QT intervals are clinically unreliable as guides to the presence of hypercalcemia. Similarly, the usefulness of the QT intervals in the diagnosis of hypocalcemia is limited by the wide distribution of normal values.